Hi Everyone,My company consists of 40 employees who continuously travel worldwide. Our email usage is very high in terms of Volume(receiving sending large attachments). We currently use POP3 services which is from a third party don't work from some parts of the world because of SMTP blocks etc.We are nowinterested in Exchange Server but areheld backwith what different IT consultants tell us. We have talked to 3 different consultants and each of them have shown us a different system architectures i.e 4 servers 1 PDC, 1 Exchange, 1 ISA and 1 Mailrelay etc and it goes on... then theres the scare of SPAM and Viruses etc and all the talk about a security appliance at the network edge, type of Processors, Ram required and the likes of it.For a scenario such as ourswhere we have 40 employees travelling worldwide we would like to know the best and most recommended type of setup right from number of servers, their role or application i.e. Exchange, ISA, PDC etc, the type of Processor, RAM HDD configuration, SPAM and Antivirus Software etc.What we also want is our Outlook 2007 to work from any part of the world. Our users do not use OWA so much so that we would like to know if RPC over HTTP really works and what does its performance depend on.Again we are looking for a reliable setup and will not compromise on costs.We are desperately looking for true guidance and any professional advice will be gladly appreciated.Thanks

Hello, Considering reliability(not talking GC/DC performance inside from AD ), youd better to have separate installed for Exchange 2007 server roles (such as mailbox server role, hub transport server role, client access server role,and Edge Transport server role). According to Microsoft recommended deployments document, I also dont recommend you install all exchange server roles on a simple Server. For more detailed information, please refer to the below article about recommended deployments. http://technet.microsoft.com/en-us/library/bb201711(EXCHG.80).aspx thanks, -Jason